p-Toluenesulfonic acid monohydrate → 5-Bromo-1-methyl-2-phenyl-1H-benzo[d]imidazole

Participants

Reaction Steps

7.8 g (26 mmol) of 4′-bromo-N-methyl-2′-aminobenzanilide was suspended in 50 mL of xylene. After the addition of 1.5 g (7.7 mmol) of p-toluenesulfonic acid monohydrate, the mixture was heat refluxed for 7 hours. After completion of the reaction, the mixture was filtered. The resulting solid was dissolved in methylene chloride, washed with a 10% potassium carbonate aqueous solution and a saturated sodium chloride solution, and dried over magnesium sulfate. The solvent was then evaporated under reduced pressure. An organic substance was also collected from the filtrate by the same washing method. The solid and the organic substance were purified by silica gel column chromatography to obtain 6.5 g of 5-bromo-1-methyl-2-phenyl-1H-benzimidazole as a white crystal (yield: 89%).

Provenance & Evidence